Two-cycle gas engine



3 Sheets-Sheet 1 |'T"'{ i l 1 ii i. A i: 'Lnm I INVENTO RV EM.TLL(-ker ATTORNEY y 7, 1935. E. M. TUCKER TWO-CYCLE GAS ENGINE Filed Feb. 29, 1952; s Sheets-Sheet 2 g a 4 a T uck er Filed Feb, 29, L952 3.Sheets-Sheet 3 lNvEN-roR ELM. Tucker ATTORN EY Patented 7,.1935

, Emmitt M. Tucker,

of California Sacramento, to Tucker Diesel Motor Co.

Calif" assitnor Ltd. a corporation Application February 20. 103:, Serial No. 595,009

This invention relates 6 in the present engine over the former particularly per intake and compression chamber I and a low-' relating to the manner of cooling the cylinder head while at the same time heating the intake manifold; the mounting of the spark plug and the method whereby the points of the same are always kept clean; the provision of a shock absorbing air cushion ing stroke; and sundry other refinements which will be apparent from the drawings and description now to follow.

These object I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

'Fig. 1 is a transverse section of my improved engine with the piston at the beginning of the flring stroke. I

Fig. 2 is a similar view with the piston at the end of the firing stroke.

Fig. 3 is a cross section on the line 3-3 of Fig. 1.

Fig. 4 is a side view detached of the sleeve piston partly in section.

Fig. 5 is a fragmentary transverse line 5-5 of Fig. 3.

Referring now more particularly to the characters of reference on the drawings, theengine comprises an outer cylinder consisting of an upsection on the er depending skirt 2 rigidly connected thereto; these two parts practically forming a, single unit I and having air cooling fins or being otherwise provided with heat transfer means.

Disposed concentric with and inside the skirt in clearance relation thereto is a hollow cylinder head 3 which is. open on its lower end. At said end the head is provided with an outwardly projecting flange 4 which rests on top of the crank case 5 of the engine. The skirt of the cylinder also has an outwardly projecting base flange 8 resting on the crank case and which is internally recessed to engage the flange 4, as shown. Bolts I secure the flange 6 to the crank case and it will be seen by the above arrangement that the head is both held down and retained in centered relation to the skirt.

Slidable on the head and also in the cylinder so as to have a running ilt with both is a sleeve or cylinder-piston 8, closed on its upper end; Said end of the piston is disposed between the head of for the piston at the end of the flrlevel adapted to 10 exam. (01. 123-50) the outer chamber I and the adjacent end of the head 3; the piston moving between these parts to within close distances of the same.

A wrist pin 8 is mounted in the piston toward its lower end which projects through vertical slots Ii lo cut in the opposite sides of the head I. A connecting rod H of ordinary character depends from the pin and engages the crank I2 of the crank shaft l3 which is journaled in" the crank case in the usual manner. The piston has op- 1 posed ports H and IS on substantially the same fully register with the adjacent ends of intake and exhaust ports l8 and I! respectively only when the piston is at the uppermost end of its strok as shown in Fig.2; these ports being uncovered by the movement of the piston on its opposite stroke. The port it communicates with the interior of the chamber 1 near the top by a by-pass l8, while the main intake passage l9 leads to the top of said chamher with a downwardly opening spring closed valve normally closing the entrance from said intake passage to the chamber.

The top of the head 3 at the sides is on a level with the bottom of the ports I6 and I1, and intermediate said sides and near the intake port It the head is provided with an upward projection 2| which extends substantially parallel to the port and forms a baflle preventing a direct flow of gases between the ports I4 and I5. Mounted in the head is a spark plug which preferably consists of a fixed electrode 22 mounted in the bailie and projecting horizontally from the same toward the intake passage. This electrode cooperates with another electrode 23 mounted in an insulation core 24 which removably projects through the head from below. The core is formed with a shoulder intermediate its ends which is engaged and clamped in place by the upper end of a tubular member 25, whose lower end projects below the bottom of the head and is provided with a lateral extension 28 projecting through the adjacent side of the crank case. The cable 21 to the core electrode extends through the extension and tubular member.

In order that the spark points or electrodes may be seen and adjusted when necessary, the outer wall of the by-pass l8 in line with and opposed to the port it is provided with an opening normally closed by a plug 28. In this manner when the piston is positioned such that the port ll registers with the port IS the plug points are rendered accessible for adjustment by a screw driver or other tool upon the removal of the plug.

In order to prevent the escape of gases vertiis connected to chamber to cally from between the chamber l and the piston and between the piston and the head 8, contracting rings 29 are provided in the chamber I above and below the intake and exhaust ports, and expansion rings are mounted on the head adjacent its upper end. To prevent the horizontal passage of gases between the ports when the latter are covered by the piston, ring segments 3| are mounted in the member I in the. horizontal plane of and on opposite sides of the ports, as shown in Fig. 3, which rings are pressed toward the piston by springs 32 in the ring grooves behind said rings.

In operation, when the piston is in its lowermost position, as shown in Fig. l, the charge to be fired is confined between the head 3 and the adjacent end of the piston and the firing impulse of course causes the piston to travel upwardly. With such movement of the piston the fresh mixture which has been confined in the chamber l with the previous down stroke of the pressed and is forced into the by-pass ll. As soon as the piston reaches the top of its stroke, the ports l4 and I6 register as previously stated and the fresh charge rushes into the piston. At the same time the exhaust ports register with each other so that the fired gases are discharged an operation which of course is aided by the sudden inflow of the fresh mixture. With such inflow of the mixture it passes directly against the plug points which are thus kept constantly clean, and any slight particles of carbon which may have settled thereon during the previous stroke are immediately blown oil? so that there is little if any chance that the plug will. become fouled.

It will be noted that at the topmost point past the upper end of when the piston arrives of'its stroke it extends the by-pass l8 and approaches very close to the head oi the chamber I, thus forming a small enclosed air cushion chamber 33 as shown in Fig. 2. With the succeeding downward stroke of the piston the valve 20 is of course opened by the tendency to vacuum then set up and another charge is drawn into the chamber tobe subsequently compressed as'above described.

The upper end of the head 8, especially 'near the spark plug, tends to become very hot with the operation of the'engine. In order therefore to both cool this top portion of the head 3 and at the same time heat the incoming mixture, I provide the following arrangement. The passage i9 a jacketed manifold 34. A conduit 35 is connected to the oil distributing line from the oil pump 38 of the engine and leads to the manifold jacket. Another conduit 31 leads from the jacket to an enclosed chamber 38 formed in the top of the head 3, the top of the chamber following the contour of the bail'le 2|. The discharge from the chamber is had by means of a tube 39 which extends upwardly into the adjacent the top of the bailie, as bottom of the tube is in alinement with the top oil hole in the connecting rod so that as the oil discharges into the head area below the chamber it will splash on the connecting rod when the latter is in its upper position and will lubricate its bearingv with the wrist pin. While the engine is in operation therefore a constant circulation of oil is fed to the manifold, thereby imparting desirable heat to the same while being relatively cooled and this relatively shown. The

. cool oil is then fed to the head chamber to maintain the same in a relatively cool condition.

piston, is now com- The lower ring 30 of the head should be kept floating in oil in order to retain the necessary pressure-tight fit with the sleeve 8. I therefore drill a passage 40 from the oil chamber ll at the head to the lower ring groove so that said groove' is constantly supplied by oil from the chamber. Another passage 4i is drilled from the opposite side of the groove through the bottom of the chamber in position to discharge onto the wrist pin 9 when the latter is at its uppermost position so as to lubricate the same. The upper rings are lubricated by the film of oil left on the sleeve wall by the lower ring.

The engine with a by-pass I8 of a certain size operates under very high compression which is valuable in certain conditions especially in airplane service especially at high altitudes. At low altitudes or on the ground however a lower'compressio'n is better. To enable the engine compression to be altered according to the needs I provide an auxiliary chamber 42 which is formed on the chamber or cylinder l outwardly of the by-pass I! and communicating therewith by means of an opening 48 at the top. This opening is provided with a butterfly or similar valve 44 having a manually operable control arm 44a, so

a relatively low operating compression arises the valve 44 is opened. Some of the charge drawn into the chamber I sequently compressed by the upward movement of the sleeve, is therefore diverted into the auxiliary chamber 42 instead of being all passed into the sleeve 8 when the latter reaches the top of its stroke. only a portion of the total charge is thus delivered into the piston or sleeve, resulting in a lowered-compression.

From the foregoing description it will be readily seen that I substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in'practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

1. In a gas engine, a fixed hollow head closed on top, a sleeve piston slidable on said head, a wrist pin secured to and extending from side to with the upper end of the connecting rod.

2. In a gas engine, a fixed hollow head closed on top, a sleeve piston slidable on said head, said piston being closed on top, means to reciprocate piston having an intake port in one side projecting above the headwhen the piston is in a predetermined position relative to the head, a baii'ie projecting upwardly from the relation to and near the ported side of the piston, and a spark plug mounted in the head from below and projecting upwardlyv therethrough so that the electrodes of the plug are exposed on the port side of the baflle.

3. In a gas engine, a fixed hollow head closed on top and open on the bottom. a sleeve piston through the valve 20 and sub-- have produced such a device as slidable on said head, a spark-plug core removthe chamber, a valve closed intake to the head of ably seated in the head and projecting upwardly the chamber, a port in one side oi! the chamber through the top from the interior or said head just beyond the head, the piston having a port adjacent one side, -the core having a shoulder to register with the chamber port when the piston intermediate its ends, and a tubular member suris at the outer end of its stroke, a by,-pass be- 5 rounding the core below and engaging the shoul-, tween the chamber port and the side of the der, said member being removably secured in the chamber near its outer end, and means to reciptop of the head and depending to a point below rocate the piston; said piston at the end or its the bottom or the same. outward stroke approaching close to the head or 4. In a gas n a fix d head, a sleeve piston the chamber and closing the adjacent end or the slidable on said head, said piston being closed at by-pass. I its end opposite the head, means to reciprocate 8. In a two-cycle gas engine, a fixed head, a the piston, the piston having an intake port in sleeve piston slidable on said head and closed at one side disposed beyond the head when the pisits outer end, a cylinder mounted in a fixed positon is in a predetermined position relative to tion about said piston, the latter having opthe head, an intake passage extending at right posed intake and exhaust ports, means to draw angles to the port and adapted at one end to a charge or mixture into the cylinder with the register with the port when the latter is in said movement of the piston toward the head, said predetermined position, a spark plug mountedin mixture being compressed with the outward the head just inwardly or the port and whose movement 1 th t by-pass from t electrodes are disposed in the plane'ol the port cylinder adjacent its outer end to an opposite a a wh in d m a a emovab e p u termination in the cylinder to aline with the in the outer wall of the passage in alinement with intake port when the piston is at the outer end an i a in relation t th p is in end or its stroke, and means controllable at will to of the passage. divert some or the compressed charge irom the 5. In a gas engine, a fixed hollow head closed by-pa55 on top, a sleeve piston slidable on said head, said 9. In a two-cycle gas en i e, afixed head, a Pi n b i closed n p. m n to pro sleeve piston slidable on said head and closed at h p st the p t h vin a in ak p n its outer end, a cylinder mounted in a fixed posine sid pr n above th h d n th p tion about said piston, the latter having opposed ton is in a predetermined position relative to the intake and exhaust ports, means to draw a charge head, an intake passage one end 01 which n w or mixture into the cylinder with the movement tioned to register with the port when the latter is of the piston toward the head, said mixture being in said predetermined position, a spark plug compressed with the outward movement oi. the mounted in the head and whose electrodes propiston, a by-pass from the cylinder adjacent its I iect into the horizontal plane of said end of the outer end to an opposite termination in the cylinpassage, and m ans provid d w th th pas t der to aline with the intake port when the piston render said electrodes accessible from outside the is at the outer end of is stroke, an auxiliary chainn n W h vi h Spark P from her having an opening communicating with the the same. by-pass, and a manually operable valve in said '40 6. In a two-cycle gas engine, a fixed head, a opening. sleeve piston slidable on said head and closed on I 10. In a gas engine having a fixed head, a t p. a yl n mounted in 1111941 Po ition abou sleeve piston slidable on said head and closed on i Pi h latte! having pp nd h r top and means to reciprocate the sleeve piston, zontally-alined intake and exhaust ports, passages the sleeve piston having an intake port for fuel in said member to communicate with said ports mixture in one side and projecting above the simultaneously, and packing rings mounted in head when the sleeve piston is in a predetermined the member to the sides of and on a level with position relative to the head; a spark plug '1. A two-cycle gas engine comprising a fixed closest to the port and whose electrodes are posi head, a piston slidable thereon, a compression tioned to be swept by the relatively coolincoming chamber in which the piston is slidable, said mixture immediately upon such mixture leaving chamber being closed on its outer end and the the port. piston being closed on that end which is disposed between the head and the closed end of EMMIT M. TUCKER. 

